Apparatus and method for feeding high-purity ammonia gas

ABSTRACT

It is an object of the present invention to provide a system for feeding a high-purity ammonia gas, where a feeding apparatus free from generation of a particle due to corrosion and not causing the formation of a corrosion or reaction product inside the gas feeding path, such as cylinder valve, pressure regulator, pressure gauge, mass flow controller, line valve and filter, is appropriately employed for the gas flow path from a gas cylinder to a production apparatus, thereby realizing more safe and highly efficient feeding of the high-purity ammonia gas without deteriorating the purity and production of a semiconductor device having higher performance. The apparatus for feeding a high-purity ammonia gas of the present invention comprises the sealing part and/or the gas contacting part which comprise a halogen-free resin. The gas flow path of feeding a high-purity ammonia gas is constituted by the above-described high-purity ammonia gas-feeding apparatus, and thereby a high-purity ammonia gas can be fed to an apparatus for producing a semiconductor device without deteriorating the gas purity.

CROSS REFERENCES OF RELATED APPLICATION

This application is an application filed under 35 U.S.C. §111(a)claiming benefit pursuant to 35 U.S.C. §119(e)(1) of the filing date ofProvision Application 60/470,895 filed on May 16, 2003 pursuant to 35U.S.C. §111(b).

FIELD OF THE INVENTION

The present invention relates to an apparatus and a method for feeding ahigh-purity ammonia gas. More specifically, the present inventionrelates to an apparatus and a method for feeding a high-purity ammoniagas, which apparatus and method can maintain the purity of a high-purityammonia gas without deterioration and decrease the contamination of asemiconductor device produced by a gas flow path constituted using ahigh-purity ammonia gas-feeding apparatus having excellentmaintainability and safety, in feeding a high-purity ammonia gas, whichis used in a semiconductor production process, to an apparatus forproducing a semiconductor device.

BACKGROUND OF THE INVENTION

The gas for use in the production of semiconductors generally includeshighly corrosive halogen-base gases such as HBr and HCl, highlydecomposable special gases such as SiH₄, and high-purity startingmaterial gases containing a constituent element for film formation, suchas NH₃. In a system of feeding such a gas, if a particle is produced dueto impurities generated from equipment or due to corrosion, this causescontamination in the inside of the semiconductor production processsystem or on the product semiconductor device, giving rise to reductionin the quality or yield. Furthermore, in the case of highly decomposablegases, the gas must be fed to the use point without undergoingdecomposition and moreover, since many of these gases are dangerous tohuman body, the gas must be inhibited to leak outside due to breakage orcorrosion.

From these reasons, the material constituting the equipment for feedingvarious highly corrosive gases or highly decomposable special gases usedin the production of semiconductors, such as cylinder valve, pressureregulator, pressure gauge, flow meter (e.g., mass flow controller), linevalve and piping, is generally stainless steel 304 or 316L (VODmaterial) or a highly corrosion-resistant stainless steel materialincluding a low- or ultralow-manganese material (VIM-VAM material) and ahastelloy material, such as Ni alloy and Co alloy. The material used forthe sealing part of the gas-feeding apparatus is a resin, particularly afluororesin because of its high chemical stability.

The fluororesin is chemically very stable and therefore, widely used inthe semiconductor production process. Specific examples thereof includepolyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF),polychlorotrifluoroethylene (PCTFE), polytetrafluoroethylene (PTFE),tetrafluoroethylene-hexafluoropropylene copolymer (FEP) andtetrafluoroethylene-perfluoroalkyl vinyl ether copolymer. These resinsare employed for many instruments.

In the production of semiconductor devices, higher integration isacceleratingly proceeding at present. However, the apparatus for feedingsuch gases for use in the semiconductor production process has a problemin that a particle is produced due to corrosion only in less than oneyear to form a corrosion or reaction product inside the gas feeding pathsystem and thereby the semiconductor device is contaminated.Furthermore, the sealing property of the gas-feeding apparatusdeteriorates to cause gas leak and this gives rise to a problem in thesafety or economics, such as interruption of the production process.

On the other hand, the high-purity ammonia gas as a starting materialgas containing a constituent element for film formation is weak in thecorrosiveness as compared with corrosive gases and is considered not tocause a problem of corrosion due to gas.

The metal material used at present for constituting a high-purityammonia-feeding apparatus is a stainless steel such as SUS316L. Theresin material used in general is a fluororesin, specifically,polychlorotrifluoroethylene (PCTFE) or polytetrafluoroethylene (PTFE).For example, Patent Document 1 (JP-A-6(1994)-24737) discloses aninvention using a fluororesin for a filter for purifying an ammonia gas.

However, in the equipment for constituting the gas flow path of feedinga high-purity ammonia gas, an “exhaust flow phenomenon” or a phenomenoncalled “inner leak”, where an ammonia gas flows downstream the gas flowpath in the closed state, is generated and due to deterioration in thesealing property, a pressure regulator in particular has a life on theorder of only from 3 to 6 months. Therefore, it is strongly demanded toenable more stable feeding of a high-purity ammonia gas over a longperiod of time.

[Patent Document 1] JP-A-6(1994)-24737

OBJECT OF THE INVENTION

It is an object of the present invention to provide a method for feedinga high-purity ammonia gas, which method comprises applying a gas-feedingapparatus including cylinder valve, pressure regulator, pressure gauge,mass flow controller, line valve and filter which apparatus is free fromgeneration of a particle due to corrosion and does not form a corrosionor reaction product inside a gas feeding system, to a gas flow path froma gas cylinder to a semiconductor producing apparatus appropriately, andthereby realizes more safe and highly efficient stable feeding of thehigh-purity ammonia gas without deteriorating the purity and productionof a semiconductor device having higher performance.

SUMMARY OF THE INVENTION

The present inventors have been earnestly studied to solve the problemsencountered in feeding a high-purity ammonia gas, and found that adehalogenation reaction takes place on contacting of the high-purityammonia gas with a fluororesin. They also found that the halogen flowedoutside the resin system due to this dehalogenation reaction corrodesand damages the metal material constituting the apparatus, as a result,the cylinder valve, pressure regulator, mass flow controller, filter orline valve used for the feeding of the high-purity ammonia gas undergoesa so-called “exhaust flow phenomenon” and must be exchanged usually in afew months.

Also, the present inventors have revealed a mechanism that the corrosionproduct generated due to the dehalogenation phenomenon is detected notin the apparatus where the corrosion product is generated but in theinside of a device producing apparatus or a gas-feeding apparatusdisposed downstream the gas flow path and therefore, the apparatus usedfor feeding a high-purity ammonia gas cannot provide the purity ofinitial feeding, as a result, contamination of a device is brought aboutat the end of the production process.

The present invention relates to the following (1) to (10).

(1) An apparatus for feeding a high-purity ammonia gas, comprising asealing part and/or a gas contacting part, which comprise a halogen-freeresin.

(2) An apparatus for feeding a high-purity ammonia gas, comprising asealing part, which comprises a sealing part body and an abuttingmaterial capable of imparting sealing property by abutting against saidsealing part body,

wherein said sealing part body comprises a halogen-free resin, and

at least the abutting part against the sealing part body of saidabutting material comprises a stainless steel, a cobalt alloy, a highlycorrosion-resistant nickel alloy or a ceramic selected from the groupconsisting of alumina, aluminum nitride and silicon carbide.

(3) The apparatus for feeding a high-purity ammonia gas as described in(1) or (2) above, wherein the halogen-free resin is selected from thegroup consisting of a polyolefin resin, a polyamide resin, a phenolresin, a xylene resin, a polyphenylene sulfide resin, a polyether etherketone resin, a polyimide resin and a polyethylene terephthalate resin.

(4) The apparatus for feeding a high-purity ammonia gas as described inany one of (1) to (3) above, wherein said halogen-free resin has aRockwell surface hardness of from R30 to R150.

(5) The apparatus for feeding a high-purity ammonia gas as described inany one of (1) to (4) above, which is a cylinder valve.

(6) The apparatus for feeding a high-purity ammonia gas as described inany one of (1) to (4) above, which is a pressure regulator.

(7) The apparatus for feeding a high-purity ammonia gas as described inany one of (1) to (4) above, which is a flow controller.

(8) The apparatus for feeding a high-purity ammonia gas as described inany one of (1) to (4) above, which is a line filter.

(9) The apparatus for feeding a high-purity ammonia gas as described inany one of (1) to (4) above, which is a line valve.

(10) A method for feeding a high-purity ammonia gas, comprisingconstituting a gas flow path of feeding a high-purity ammonia gas byusing the high-purity ammonia gas-feeding apparatus as described in anyone of (5) to (9) above, and feeding a high-purity ammonia gas withoutdeteriorating the gas purity.

EFFECT OF THE INVENTION

According to the present invention, an appropriate resin sealant and anappropriate metal sealant are selected and used, so that a high-purityammonia gas can be safely and stably fed without deteriorating thepurity. In other words, the occurrence of a dehalogenation phenomenoncan be prevented in the gas-feeding apparatus having resin sealing inview of structure, such as gas cylinder valve, flow controller (e.g.,mass flow controller), pressure gauge, gas filer and line valve, and thegeneration of an exhaust flow phenomenon can be greatly reduced in thepressure regulator.

Furthermore, the occurrence of a dehalogenation phenomenon can also beprevented in the chamber for producing a semiconductor device or theequipment used in discharging an ammonia gas outside the apparatus fromthe chamber by using the present invention.

Therefore, according to the present invention, at the time of feeding ahigh-purity ammonia gas, the elution of halogen into the feed system dueto the dehalogenation reaction can be suppressed and a corrosion productor a reaction product with halogen is not formed, so that the purity ofgas can be maintained and a semiconductor device can be produced withhigh efficiency.

DETAILED DESCRIPTION OF THE INVENTION

The apparatus for feeding a high-purity ammonia gas of the presentinvention is characterized in that the sealing part and/or the gascontacting part of the feeding apparatus, which parts comprise ahalogen-free resin, in order to have sufficiently high durabilityagainst an ammonia gas and not cause a dehalogenation phenomenon by theammonia gas.

Further, it is necessary to consider that apparatus needs to havecorrosion resistance to a very slight amount of impurities contained ina gas fed and impurities entered inside by opening thereof to air, andthat the apparatus will suffer from corrosion caused by propertiesinherent in the resin such as permeability and water absorptionproperties.

Therefore, the high purity ammonia gas feeding apparatus according tothe invention has a sealing part which comprises a sealing part body andan abutting material capable of imparting the sealing property byabutting on the sealing part body, and the sealing part body comprises ahalogen-free resin and the abutting material preferably has propertiesnecessary for the ammonia gas feeding apparatus.

It is known that, in feeding ammonia gas, as the sectional area of thegas feeding part of the abutting part constituting the sealing part isvery small, ammonia gas is passed through at a very high rate, or rapidchange of a volume of the gas passing part induces adiabatic expansionand thereby the ammonia gas is cooled and is liquefied.

Therefore, it is necessary to select materials having steady functionsin the abutting part. For example, when ammonia gas is passed through ata low flow rate and stainless steel is employed for the material, it ispreferred to select austenite materials having excellent corrosionresistance such as SUS304 and SUS316L. While, when ammonia gas is passedthrough at a very high flow rate, it is preferred to select martensiteor precipitation hardening stainless steel having excellent corrosionresistance and uniform strength such as SUS630 or SUS631.

As is clear from the above, in the ammonia gas feeding apparatus of thepresent invention, at least the abutting part against the sealing partbody of the abutting material preferably comprises a stainless steel, acobalt alloy, a highly corrosion-resistant nickel alloy or a ceramicselected from the group consisting of alumina, aluminum nitride andsilicon carbide.

Also, the ceramic may be selected from the group consisting of tungstencarbide (WC), chromium carbide (Cr₃C₂), titanium carbide (TiC), titania(TiO₂), chromium oxide (Cr₂O₃), zirconia (ZrO₂), titanium nitride (TiN)and chromium nitride (CrN). These ceramics may be used as a mixture.

The abutting part against the sealing part body of the abutting materialcomprises the above-described metal material having a sufficiently highcorrosion resistance to ammonia gas and the like, so that a particle, acorrosion product or reaction product cannot be generated.

The halogen-free resin for use in the present invention is preferablyselected from the group consisting of a polyolefin resin, a polyamideresin, a phenol resin, a xylene resin, a polyphenylene sulfide resin, apolyether ether ketone resin, a polyimide resin and a polyethyleneterephthalate resin. By using such a resin, the dehalogenationphenomenon due to ammonia gas can be prevented and the life of thesealing part can be prolonged.

The halogen-free resin preferably has a Rockwell surface hardness of R30to R150. When the Rockwell surface hardness is less than R30, thestrength of resin tends to be insufficient. When the Rockwell surfacehardness is more than R150, it tends to be difficult to maintain theairtightness since the resin becomes too hard. The Rockwell surfacehardness is one of the indicator which indicates the mechanical strengthof resin and can be measured by the method described in JIS K7202.

The resin used in the invention may contain a filler in order to improvethe mechanical strength. Examples of the filler are not particularlylimited as long as they have corrosion resistance to ammonia, and mayinclude inorganic fillers such as magnetic powder, metal, oxide,hydroxide, silicate, carbonate, sulfate and carbons, or organic fillers.

The content of the filler varies depending to conditions such as densityof the filler. It is preferred to add an proper amount of the fillerwithin the limit of not missing the object of the invention because whena large amount of the filler is added, not only the processability isdeteriorated, but also the flexibility of a resulting composition isinsufficient.

By virtue of the above-described constitution of the apparatus forfeeding a high-purity gas of the present invention, not only thedehalogenation phenomenon due to high-purity ammonia gas and the exhaustflow phenomenon or inner leak can be prevented but also the life of thegas-feeding apparatus can be prolonged, so that a high-purity ammoniagas can be stably fed over a long period of time.

Examples of the apparatus for feeding a high-purity ammonia gas of thepresent invention include a cylinder valve, a pressure regulator, a flowcontroller, a line filter and a line valve.

The method for feeding a high-purity ammonia gas of the presentinvention is characterized in that the gas flow path of feeding ahigh-purity ammonia gas is constituted by using the above-describedhigh-purity ammonia gas-feeding apparatus and thereby, the high-purityammonia gas can be stably fed to an apparatus for producing asemiconductor device without deteriorating the gas purity.

The apparatus and the method for feeding a high-purity ammonia gas ofthe present invention can be applied to an apparatus for producing asemiconductor device by using a high-purity ammonia gas as a startingmaterial and also be applied to, for example, equipment used indischarging a high-purity ammonia gas.

EXAMPLES

The present invention is described below by referring to Examples,however, the present invention is not limited by these Examples.

Examples 1 to 4

FIG. 1 shows a testing device for testing the corrosiveness of thesealing part of a gas-feeding apparatus by a high-purity ammonia gas,and the exhaust flow phenomenon or the like in the pressure regulator.As shown in FIG. 1, a gas cylinder 1 was connected with a pressureregulator 2 through piping and pressure gauges 3 and 4 were disposedbefore and after the pressure regulator 2 to provide a structure thatthe malfunction of the pressure regulator 2 can be confirmed by thechange appearing in the indicated values of two pressure gauges. The gasused was recovered and treated by a gas harm-removing apparatus 6. FIG.2 is a simplified view showing the inner structure of the pressureregulator 2 used in this Example.

The resin sealant constituting the resin sheet 8 as a sealing part bodyshown in FIG. 2 and the metal sealant constituting the regulating valvebody 11 as an abutting material abutted against the resin sheet 8 to cutoff the gas flow path are shown in Table 1. For other metal portionsconstituting the pressure regulator 2, stainless steel 316L was used.

The resin used for constituting the resin sheet 8 was a phenol resin inExample 1, a polyphenylene sulfide resin (PPS) in Examples 2 and 3, anda polyether ether ketone resin (PEEK) in Example 4. The metal materialconstituting the regulating valve body 11 was a stainless steel material(SUS316L) in Examples 1, 3 and 4 and Hastelloy C-22 in Example 2.

A gas cylinder filled with 20 kg of a high-purity ammonia gas having apurity of 6N (produced by Showa Denko K.K.) was installed in anapparatus and the apparatus itself was placed in an atmosphere of 25° C.Thereafter, the flowing of gas was continued 100 days at a flow rate of1.0 liter/min for 5 hours/day.

Comparative Examples 1 and 2

In the same manner as in Examples, as shown in FIG. 1, a gas cylinder 1was connected with a pressure regulator 2 through piping and byproviding a structure that the state of the sealing material can bejudged and confirmed by the change appearing in the indicated pressurevalues, a test was performed. The gas used was recovered and treated bya gas harm-removing apparatus 6.

The resin sealant used for constituting the resin sheet 8 as a sealingpart body in the pressure regulator 2 was a polychlorotrifluoroethylene(PCTFE) resin and the metal sealant used for constituting the regulatingvalve body 11 as an abutting material abutted against the resin sheet 8to cut off the gas flow path was stainless steel 316L in ComparativeExample 1 and Hastelloy C-22 in Comparative Example 2. For other metalportions constituting the pressure regulator 2, stainless steel 316L wasused.

In the same manner as in Examples, a gas cylinder filled with 20 kg of ahigh-purity ammonia gas having a purity of 6N was installed in anapparatus and the apparatus itself was placed in an atmosphere of 25° C.Thereafter, the flowing of gas was continued 100 days at a flow rate of1.0 liter/min for 5 hours/day. TABLE 1 Regulating Valve Resin Sheet 8Body 11 Example 1 phenol resin SUS316L Example 2 polyphenylene sulfideresin, Hastelloy C-22 PPS Example 3 polyphenylene sulfide resin, SUS316LPPS Example 4 polyether ether ketone SUS316L resin, PEEK Comparativepolychlorotrifluoroethylene SUS316L Example 1 resin, PTCFE Comparativepolychlorotrifluoroethylene Hastelloy C-22 Example 2 resin, PTCFE

After the completion of the flowing test of a high-purity ammonia gasfor 100 days, a test of confirming the operating state of each apparatusin Examples 1 to 4 and Comparative Examples 1 and 2 was performed. Inthis test, the pressure regulator 2 was turned into the CLOSE state andthe effectiveness of gas-sealing property (exhaust flow phenomenon) whenthe pressure regulator 2 was in the CLOSE state was judged from thechange in the indicated values of two pressure gauges 3 and 4 disposedbefore and after the pressure regulator 2. More specifically, it wasfirst confirmed that a residual gas is not present in the apparatussystem and the pressure gauges 3 and 4 each indicates atmosphericpressure. Then, a helium gas pressure of 1.0 MPa was applied to thepressure gauge 3 from the gas cylinder side and after holding this statefor 60 minutes, the pressure indicated by the pressure gauge 4 wasrecorded. The results are shown in Table 2. TABLE 2 Pressure PressureJudgement of Gauge 3 Gauge 4 Exhaust Flow State of Resin (MPa) (MPa)Phenomenon (appearance) Example 1 1.0 0.0 none no change Example 2 1.00.0 none no change Example 3 1.0 0.0 none no change Example 4 1.0 0.0none no change Comparative 0.4 0.48 present changed to Example 1 brownComparative 0.9 0.08 slightly changed to Example 2 present brown

As seen from Table 2, in the pressure regulators of Examples 1 to 4using, as the resin sealant, a phenol resin, a polyphenylene sulfideresin or a polyether ether ketone resin, the flow of gas was closed inthe CLOSE state after the completion of the test and a so-called“exhaust flow phenomenon” was not observed. On the other hand, inComparative Examples 1 and 2, the numerical value of the pressure gauge4 was increased and this reveals that the gas was flowing.

From comparison of Examples 1, 3 and 4 and Comparison Example 1 whereSUS316L was used for the abutting material (regulating valve body 11) ofthe pressure regulator, the pressure regulator of Example having asealing part body formed of a halogen-free resin was verified to haveexcellent durability as compared with the pressure regulator ofComparative Example 1 using a conventional halogen-containing resin.

The difference of Comparative Example 1 and Comparative Example 2 isattributable to the difference in the metal sealant constituting theabutting material of the pressure regulator 2. In both ComparativeExamples, a fluororesin was used as the resin sealant for the sealingpart body and an “exhaust flow phenomenon” of causing flow of gas in thedownstream direction was observed from the indicated value of thepressure gauge 4. However, in the pressure regulator of ComparativeExample 2 where the metal sealant constituting the abutting materialabutted against the sealing part body had improved corrosion resistance,the indicated value of the pressure gauge 4 was smaller than inComparative Example 1 and the level of “exhaust flow phenomenon” waslower. That is, the highly corrosion-resistant nickel alloy (hastelloymaterial) was proved to have more excellent corrosion resistance thanthe conventional stainless steel. Also, it was revealed that the sealingperformance was deteriorated due to change in quality of the resinsealant by a dehalogenation phenomenon and the eliminated halogenaffected the meal sealant.

After the completion of test, the pressure regulators used in Examplesand Comparative Examples each was disassembled and the change in weightof the resin sealant taken out was investigated. The results are shownin Table 3. TABLE 3 Variation in Resin Sheet 8 Weight (mg/mm²) Example 1phenol resin +6.1 Example 2 polyphenylene sulfide resin, PPS 0.0 Example3 polyphenylene sulfide resin, PPS 0.0 Example 4 polyether ether ketoneresin, PEEK 0.0 Comparative polychlorotrifluoroethylene resin, −12Example 1 PTCFE Comparative polychlorotrifluoroethylene resin, −26Example 2 PTCFE

The variation in weight of the resin was a numerical value obtained bymeasuring the increase or decrease of weight between before and afterthe test and dividing the obtained value by the entire surface area ofthe resin seal.

It is seen from the results in Table 3 that the phenol resin of Example1 has excellent corrosion resistance against an ammonia gas and can beused as the resin sealant, despite the increase of weight due topermeation of ammonia gas. As seen from the results of Examples 2, 3 and4, the polyphenylene sulfide resin and polyether ether ketone resin werenot changed in the weight and revealed to have excellent corrosionresistance against an ammonia gas. The weight of the PTCFE resin used inComparative Examples 1 and 2 was decreased constantly. The fact that thenumerical value of Comparative Example 1 was smaller than the numericalvalue of Comparative Example 2 is considered on the ground that a darkbrown substance was outwardly attached on the resin measured because acorrosion product of the metal sealant corroded by dehalogenation wasattached to the resin.

After the completion of the test, the surface of the metal sealantconstituting each pressure regulator used in Example 1 and ComparativeExample 1 was observed by a scanning electron microscope. The resultsare shown in FIG. 3.

As seen from FIG. 3, in Comparative Example 1, the halogen-containingproduct produced by the dehalogenation reaction between PTCFE andammonia reacted with the metal sealant to generate serious corrosion. Onthe other hand, the metal sealant of Example 1 was not corroded andmaintained metal gloss. As a result, the exhaust flow phenomenon was notobserved at all in the pressure regulator.

FIG. 4 shows the change in constituent elements of the resin sealantused for the pressure regulator of Comparative Example 1 after thecompletion of the test. The elemental analysis was preformed by anenergy dispersive X-ray analyzer (EMAX, manufactured by Horiba Ltd.).

The amount of the Cl element as a constituent element of PTCFE detectedbefore the test was 36.1 cps but decreased to 0.93 cps after thecompletion of the test and this reveals that the percentage of theresidual amount of chlorine element in the analysis range is only 2.5%.

The surface of each diaphragm plate constituting the diaphragm valve(line valve 5) provided downstream the gas flow path from the pressuregauge 4 used in Example 1 and Comparative Example 1 was observed by anelectron microscope after the completion of the test and the presence orabsence of reaction product and the like was inspected. Furthermore, theproduced reaction product was subjected to elemental analysis by anenergy dispersive X-ray analyzer. The results obtained are shown in FIG.5.

In Example 1, formation or the like of foreign matters was not observedon the surface of the diaphragm plate of the line valve 5 and only thecomponents of stainless steel were detected by the elemental analysis ofthe diaphragm plate surface. In Comparative Example 1, the observationthrough an electron microscope revealed that a reaction product remainedor accumulated on the surface of the diaphragm plate of the line valve5. The elements in this portion of the photograph were analyzed, as aresult, a large amount of chlorine was detected in addition to thecomponents of the stainless steel constituting the diaphragm plate.

Therefore, the corrosion product formed by the dehalogenation reactionin the pressure regulator 2 was proved to reach the downstream linevalve 5 by riding on the gas flow. In Example 1, such a phenomenon wasnot observed and this reveals that the purity of the high-purity ammoniagas was maintained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view showing the testing device used inExamples.

FIG. 2 shows a schematic view showing the inner structure of thepressure regulator used in Examples.

FIG. 3 shows electron microphotographs of the surface of the metalsealant constituting the pressure regulator after the gas flow test.

FIG. 4 shows charts showing constituent elements of the resin sealantconstituting the pressure regulator before and after the gas flow test.

FIG. 5 shows electron microphotographs of the surface of the diaphragmplate constituting the line valve 5 after the gas flow test and chartsshowing the elemental analysis results.

DESCRIPTION OF REFERENCE NUMERALS

-   1 gas cylinder-   2 pressure regulator-   3 pressure gauge for inlet gas of pressure regulator-   4 pressure gauge for outlet gas of pressure regulator-   5 line valve-   6 gas harm-removing apparatus-   7 pressure regulating shaft-   8 resin sheet-   9 spring-   10 diaphragm plate-   11 regulating valve body

1. An apparatus for feeding a high-purity ammonia gas, comprising asealing part and/or a gas contacting part, which comprise a halogen-freeresin.
 2. An apparatus for feeding a high-purity ammonia gas, comprisinga sealing part, which comprises a sealing part body and an abuttingmaterial capable of imparting sealing property by abutting against saidsealing part body, wherein said sealing part body comprises ahalogen-free resin, and at least the abutting part against the sealingpart body of said abutting material comprises a stainless steel, acobalt alloy, a highly corrosion-resistant nickel alloy or a ceramicselected from the group consisting of alumina, aluminum nitride andsilicon carbide.
 3. The apparatus for feeding a high-purity ammonia gasas claimed in claim 1 or 2, wherein said halogen-free resin is selectedfrom the group consisting of a polyolefin resin, a polyamide resin, aphenol resin, a xylene resin, a polyphenylene sulfide resin, a polyetherether ketone resin, a polyimide resin and a polyethylene terephthalateresin.
 4. The apparatus for feeding a high-purity ammonia gas as claimedin any one of claims 1 to 3, wherein said halogen-free resin has aRockwell surface hardness of from R30 to R150.
 5. The apparatus forfeeding a high-purity ammonia gas as claimed in any one of claims 1 to4, which is a cylinder valve.
 6. The apparatus for feeding a high-purityammonia gas as claimed in any one of claims 1 to 4, which is a pressureregulator.
 7. The apparatus for feeding a high-purity ammonia gas asclaimed in any one of claims 1 to 4, which is a flow controller.
 8. Theapparatus for feeding a high-purity ammonia gas as claimed in any one ofclaims 1 to 4, which is a line filter.
 9. The apparatus for feeding ahigh-purity ammonia gas as claimed in any one of claims 1 to 4, which isa line valve.
 10. A method for feeding a high-purity ammonia gas,comprising constituting a gas flow path of feeding a high-purity ammoniagas by using the high-purity ammonia gas-feeding apparatus as claimed inany one of claims 5 to 9, and feeding a high-purity ammonia gas withoutdeteriorating the gas purity.